Subsonic
Yup, true of most anything. Nothing new, only history we’re ignorant of. 😉 One thing to remember is Ernest Jones lost his right leg below the knee during WWI. So he learned to swing with his arms.
If you ever want to test Jones’s, Boomer’s, De La Torre’s or Flick’s arm swing theory try hitting a driver while on your knees.
It’s an all arms swing. No weight shift, no hip turn, no ground forces stuff. And you’ll be surprised how far and straight you hit it. 😉